Millions of illegal immigrants are marching in America’s streets and boycotting jobs, schools and merchants. Their explicit purpose is to blackmail our government into granting rights to which they are not entitled.

These activities demonstrate two realities: First, life is good in this country and the opportunities for economic advancement are extraordinary for those willing to work hard.

Second, life is typically not so good in Mexico and the other Latin American nations from which these illegal aliens principally come. Unfortunately, if present political, economic and social trends continue south of our border, there will likely be many more immigrants coming here unlawfully in search of better lives, and to flee increasingly hard ones in their own countries.

In fact, a prospective surge in illegal immigration — perhaps coupled with a further radicalization of those already in this country — are just some of the reasons why these worrisome trends should command far greater attention from American policymakers and citizens alike. Despite the serious and almost-without-exception adverse implications of events throughout Central and South America for our strategic, trade and security interests, however, neither the Bush administration nor either party in Congress is doing much to address them.

Among the indicators of trouble ahead are the following ominous developments:

 Fidel Castro has been rescued from oblivion by the oil wealth and vaulting strategic ambitions of his most promising protege, Venezuela’s Hugo Chavez. The two authoritarians have adopted a new strategy, born of the realization that radical anti-American leftists can be brought to power throughout the hemisphere the same way Mr. Chavez was — by ballots, rather than bullets.

Funding and organizational support from Venezuela is making the electoral playing-field uneven across the region, giving a formidable advantage to populist revolutionaries over their democratic opponents. Once in office, the latter can rely not only on money from Mr. Chavez and his Islamofascist (for example, Iranian) and Chinese friends. They can also elicit muscle from Mr. Castro’s foreign legion (communist Cuban special forces, police, praetorian guards, doctors and teachers) to help consolidate control and eliminate their opponents.

 This phenomenon is already well-advanced in Bolivia, where Evo Morales was elected president in December, after fomenting populist upheavals to topple not one but two elected governments. He has moved rapidly in ensuing months to neutralize the parliament, constitution and judiciary that might check his steady accretion and exercise of power.

 In Peru, another would-be dictator, Ollanta Humala, has won the first round of balloting to replace outgoing President Alejandro Toledo. While it is not clear at this writing whether he will prevail in the upcoming runoff, Mr. Humala’s inflammatory rhetoric (threatening the country’s political elite and its constitutional democracy, admiring the violent terrorist group known as the Shining Path and signaling a willingness to go to war with neighboring Chile) represents a frightening prospect for Peru, the region and U.S. interests. Even if Mr. Humala loses, it is not clear he will refrain from fomenting trouble for the new government — and the rest of us.

 Bolivia and Peru are relatively distant and it is seductive to discount them as security problems for the United States. The same cannot be said of Mexico, which will hold a presidential election in July. Polls have long suggested the likely winner will be Andres Manuel Lopez Obrador, the rabidly anti-American former mayor of Mexico City.

Like others of his persuasion, Lopez Obrador’s bid appears to have benefited from financial and help on the ground from his soul mates in Caracas and Havana, who clearly relish the prospect of extending their axis to the border of the United States. While the race has of late become increasingly competitive, as the conservative PAN Party’s candidate Felipe Calderon has gained ground, Washington confronts the distinct possibility of an explicitly hostile government in Mexico.

The implications of such an outcome could be far-reaching for the integrity of our southern frontier, illegal immigration, drug-trafficking, terrorism, trade and the radical “reconquista” movement (which is intent on “taking back” at least parts of the United States for Mexico).

 Then, there is Nicaragua. All other things being equal, the Marxist Sandinista party still led by Comandante Daniel Ortega is poised — with help, ironically, from both the Venezuelan and American governments — to win national elections in November. For his part, Mr. Chavez is pumping money and possibly agents into his allies’ campaign.

The Bush administration is unabashedly and ham-handedly backing Eduardo Montealegre, a foreign minister under discredited former President Arnoldo Aleman. Mr. Montealegre has fractured the anti-Sandinista democrats and his candidacy seems likely to precipitate their defeat. Yet, Washington refuses to reconsider and either support the candidate of the largest and best organized pro-democracy party, the Constitutionalist Liberals, because of its association with Mr. Aleman — or at least to remain neutral.

The consequence of all these elections may well be the complete undoing of Ronald Reagan’s legacy of successfully countering and, with the notable exception of Mr. Castro’s Cuba, defeating totalitarianism in our hemisphere. At some point in the not-too-distant future, the question will be asked, probably with political repercussions: “Who lost Latin America?”

There is still time for the Bush administration and Congress to avoid this stigma by countering these trends and their strategic implications. But to do so, they will have to engage far more vigorously against Latin America’s enemies of freedom, investing considerably greater human and financial resources, high-level attention and political capital in once again securing our hemisphere.

Frank J. Gaffney Jr. is president of the Center for Security Policy and a columnist for The Washington Times.